has commanded us" over a mitzvah derabanan.®® On Rosh Hodesh, however, when the recitation of Hallel was based on minhag and not rabbinic enactment, it was not at all obvious that a berakhah should be said. The Talmud ® relates that no benediction was recited over the beating of the aravot precisely because that practice was a minhag. Rashi explains that a minhag differs from a taganah in that no benediction is to be recited over it; indeed, how can one say"who has commanded us" over an act which was voluntarily adopted by the people and which was not imposed upon them either by the Torah or the rabbis?** Such a blessing is a berakhah I'vatalah, a violation of the prohibition of taking God ’s name in vain.®® This position is held consistently by the"Rashi School" and by Maimonides , who states flatly that"one does not recite a benediction over a minhag."® On the other hand, the recitation of a berakhah over Hallel on Rosh Hodesh is attested in gaonic times® and was accepted in northern Europe , where the Tosafists developed theories to justify the practice. R. Ya'aqov Tam argued that the relevant Talmudic passages prove that a benediction was recited. For example, if no berakhah were said, Rav would not have thought at first to stop the Babylonians from saying Hallel, nor would the Talmud ? have raised the issue of interruptions during the Hallel. Without a benediction,"Hallel" is simply the recitation of psalms, to which there can be no particular objection and which may be interrupted. With a berakhah it becomes a ritual act, and halakhic concerns--berakhah I'vatalah, interruptions--are thereby in order. The fact is, he contended, we do say benedictions over minhagim, such as the giddush on the second day of Yom Tov. As for the aravah we cannot compare that practice, the mere shaking of branches, with the Hallel, which resembles reading from Torah , over which we do say a berakhah.*®
These arguments over this issue closely paralleled those surrounding a similar minhag: the custom among women in Ashkenazic lands to recite benedictions when performing positive, time-bound commandments to which they were neither Toraitically
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